Papers by Keyword: SEM Analysis

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Authors: S. Manikandan, J. Jancirani
Abstract: This study investigated the preparation of nanosized crystalline SiC powders from micro sized Silicon Carbide powder at room temperature through high energy ball milling. Silicon carbide was milled with hardened steel balls and ball milling media under identical conditions of ball mass to powder mass ratio 10:1 and target milling times of 60 h. The sample was taken out after every 20 hours of milling and it was characterized for its crystalline size, lattice strain, and percentage of crystalline by using X-Ray Diffractometer (XRD). It was found that for the 60 hours The size, shape and texture of the fresh as well as nanostructured Silicon carbide powder were studied using Scanning Electron Microscopy (SEM). The raw Silicon carbide powder particles were mostly angular in shape. The shape of the 60h milled particles is irregular and the surface morphology is rough.
Authors: Hiroaki Takeda, Han Joong Sang, Takashi Tateishi, Spela Kunej, Colin Leach, Robert Freer, Takuya Hoshina, Takaaki Tsurumi
Abstract: BaTiO3–(Bi1/2K1/2)TiO3 (abbreviated as BT-BKT) solid solution ceramics, as a lead-free PTC (positive temperature coefficient of resistivity) thermistor material usable over 130°C, has been synthesized by sintering in N2 atmosphere and after annealing in air over 1200°C. In the BT-BKT ceramics with PTC property, the impedance/modulus spectroscopic plots have revealed that a third resistance-capacitance (RC) response besides grains and grain boundaries. Using the remote electron beam induced current (REBIC) configuration, imaging has revealed EBIC contrast consistent with the presence of negatively charged electrostatic grain boundary barriers in the BT-BKT semiconducting ceramics.
Authors: Lu Yang Ren, Mohsen Masoumi, Henry Hu
Abstract: Metallographic analyses on microstructure of squeeze cast magnesium alloy AM50 with different levels of calcium addition are performed via optical microscopy (OM), and scanning electron microscopy (SEM). The OM results show the calcium has a grain refining effect on the base alloy AM50 with the level of Ca addition up to 2 wt.%. As the Ca content further increases, its grain refining effect becomes limited. The SEM observation reveals the addition of 2 wt.% Ca to the AM50 alloy leads to the formation of a continuous network of eutectic phases along grain boundaries while the discontinuous divorced secondary eutectic β-Mg12Al17 is present in the microstructure of AM50 containing also the primary α-Mg, and Mn-Al intermetallic particles. The elemental mapping by the energy dispersive spectroscopy (EDS) indicates the presence of the major alloying elements of Al and Ca along grain boundaries in the squeeze cast AM50 alloy with Ca addition.
Authors: Martina Lovrenić-Jugović, Zdenko Tonković, Ljerka Slokar
Abstract: This paper presents the results of an experimental and numerical investigation of the tensile behaviour of glass fibre reinforced epoxy composite for incremental and cyclic creep-recovery load conditions. The proposed constitutive model incorporates linear viscoelasticity coupled with damage and viscoplasticity for prediction of the creep-recovery responses. The material parameters are determined by fitting the experimental results. Scanning electron microscopy (SEM) of composite fracture surfaces is performed to explain the failure mechanisms. A computational algorithm for the integration of the proposed constitutive model at the material point level is derived and implemented into the finite element code ABAQUS. The model predictions are found to be in good agreement with the experimental data.
Authors: Peter Kaali, György Czél
Abstract: In this study the degradation and ion/zeolite release processes of in vitro aged zeolite loaded polyurethane composites were evaluated. Two in vitro artificial aging solutions were used; artificial lysosomal fluid (ALF) and Gamble ́s solution and the total exposure time was 12 weeks. Periodically, SEM micrographs were taken of the surface of polyester type polyurethane-zeolite composites. After exposure to ALF solution the samples showed round holes and a rougher surface in general over time. Micrographs of the samples immersed in Gamble’s solution exhibited different signs of degradation with damage features on the surfaces, understood as black holes and a rougher surface pattern. In addition varying amount of salt was also observed on the surfaces that might influence the ion/zeolite release. Furthermore, the zeolite filler caused remarkable changes in mechanical properties after the aging process, which could not be discerned.
Authors: Wei Yun Wang, Ai Min Li, Xiao Min Zhang
Abstract: Water structure present in sewage sludge with different moisture content was analyzed by differential scanning calorimeter(DSC).The sharp endothermic peaks that appeared at 6.14°C(95.87%wet basis),5.22°C(87.20%wet basis),1.33°C(71.20%wet basis).The calculation results , amount of bound water based on peak temperature and peak area, could account for stick phase of sewage sludge combined with SEM analysis results. Finally,mechanical mechanism of different phases(liquid phase, sticky phase, granule phase) were tentively described by schematic diagrams.
Authors: Siti Zulaiha Hairaldin, Wan Md Zin Wan Yunus, Nor Azowa Ibrahim
Abstract: In this study, Octadecylamine Modified montmorillonites (ODAMMT) were used to prepare polylactide/polycaprolactone (PLA/PCL) clay nanocomposites. PLA and PCL were blend using an internal mixer by melt blending method. The other sample was blend with natrium monmorillonite (NaMMT) and Octadecylamine modified monmorillonite to produce PLA/PCL-NaMMT and PLA/PCL-ODAMMT. To characterize the polymer nanocomposite, X-ray diffraction (XRD), FTIR and SEM analysis were conducted. Comparison of morphology were made up between neat PLA/PCL, PLA/PCL with presence of of montmorillonite and octadecylamine modified monmorillonite respectively based on SEM micrograph. The number-average diameter was calculated for PLA/PCL, PLA/PCL-NaMMT, and PLA/PCL-ODAMMT.
Authors: Ikilem Gocek, Reyhan Keskin, Guralp Ozkoc
Abstract: In the present study, glass fiber reinforced Polyamide 66 composites were produced using laboratory type twin screw extrusion and injection molding processes. The glass fiber reinforcement was applied at 1, 10, 15, 20, 25 and 30 wt% loadings. The morphological structure of the samples and failure modes of glass fiber reinforced Polyamide 66 composites were investigated using scanning electron microscopy (SEM) analysis on fractured surfaces of tensile tested samples in this study.
Authors: Suresh Sagadevan, Priya Murugasen
Abstract: Copper Oxide (CuO) nanoparticles were synthesized by the wet chemical method. The crystal structure and grain size of the particles were determined, using X-ray diffraction (XRD). The particle size and morphology were studied using the scanning electron microscope (SEM). The dielectric properties of CuO nanoparticles were carried out at different temperatures. The variation of the dielectric constant and dielectric loss were studied. The dielectric constants of the CuO nanoparticles are high at low frequencies, and decrease rapidly when the frequency is increased. Further, electronic properties like valence electron plasma energy, Penn gap, Fermi energy and electronic polarizability of the CuO nanoparticles, were estimated.
Authors: Wei Chen Xue, Kai Fu
Abstract: Fiber reinforced plastic (FRP) composite which has high strength, high fatigue resistance, low density, and better corrosion resistances is desirable characteristics for bridge applications, especially decks. According to the ACI 440.3R04, Glass fiber reinforced plastic (GFRP) bridge deck samples were immersed into the simulated concrete environment at 60 for 92d (corresponds to the natural environment 25 years). The results show that, with the time increased, the interlaminal shear strength of GFRP bridge decks decreased significantly. After being exposed to the simulated concrete environment for 3.65d, 18d, 36.5d and 92d, the interlaminal shear strength degradation of GFRP bridge decks were 18.69%, 25.90%, 50.93% and 53.74%, respectively. The micro-formation of the GFRP bridge deck sample surface was surveyed under scanning electron microscopy (SEM), which indicated that with the aging time increased, corrosion pits in the surface of GFRP bridge decks became more obviously and the interface between fiber and resin was severely damaged. Therefore, the degradation of FRP under the simulated concrete environment should be considered in the design of FRP bridge decks.
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